Fuel system mountable to a vehicle frame rail

ABSTRACT

A fuel system is provided that includes a fuel system frame and in some cases access steps. The frame can be mounted to a vehicle frame rail. Bracket assemblies can be coupled to the fuel system frame at a plurality of positions. The fuel tank can be mounted at neck portions thereof and can be supported on the frame rail between the neck portions, e.g., spaced a distance from the neck portions in a longitudinal direction of the fuel system. The access steps can be non-rectangular to provide a wide stepping portion even if the fuel system includes large tanks. The steps can be directly supported by an outside surface of the tank.

CROSS-REFERENCE

This application is a continuation of PCT Application No.PCT/US2020/023154, filed Mar. 17, 2020, which claims the benefit of U.S.Provisional Application No. 62/822,439, filed Mar. 22, 2019. Each of theforegoing applications is hereby incorporated by reference in itsentirety herein.

BACKGROUND OF THE INVENTION Field of the Invention

This application relates to fuel systems that can be mounted to alateral or side portion of a vehicle frame rail.

Description of the Related Art

Compressed natural gas (CNG) is an alternative fuel that provides manyadvantages. CNG fuels burn cleaner than other combustion fuels forvehicles. CNG also can be more cost effective.

CNG fuel systems can come in several forms. One form employs a Type IVfuel tank constructed with a polymeric liner. Carbon fiber wrappedaround the liner can reinforce the liner, to produce a fuel tank strongenough for use on heavy-duty trucks and other vehicles. The fuel tankcan have a boss sealing each of the end portion of the fuel tank. Theboss can provide access to the fuel tank for filling and dispensing thefuel contained therein. A side mounted fuel system can include a frameto support the fuel tank on a side or lateral portion of a vehicle.Straps can support central portions of the fuel tank within the frame.Some fuel tanks also can be supported at one or both ends at the bosses.

SUMMARY OF THE INVENTION

While the side mounted fuel system is known, complications in mountingthe fuel system can arise. Straps adds cost, complexity, and a failuremode to the fuel system. Also, other components are mounted to thelateral portion of the frame rail. So it can be challenging to locatethe fuel system conveniently relative to these other components. A needexists to provide improved side-mounted fuel systems. There is a needfor improved assemblies and systems that can be more flexibly connectedto the frame rail, e.g., a two or more positions spaced along the framerail. There is a need for improved assemblies and systems that support afuel tank at a boss portion. Also, there is a need for an improved cabaccess system. These improvements can enable larger tanks to besupported to a lateral portion of a frame rail while not extending thewidth of the vehicle at the tank beyond acceptable limits.

In one embodiment, a fuel system is provided that includes a fuel systemframe, a first bracket, and a second bracket. The fuel system frame hasa first position and a second position spaced apart from the firstposition. The first bracket is configured to connect to the fuel systemframe at the first position or at the second position to support thefuel system from either the first position or the second position. Thesecond bracket has a first portion configured to mate with the firstbracket and a second portion configured to connect to a vehicle framerail.

The first position and the second position allow the first and secondbrackets to be located at any one of a plurality of different vehicleframe rail positions along the frame rail without requiring the movementof the fuel system frame.

The first position and the second position allow the fuel system to belocated in any one of a plurality of different vehicle frame railpositions along the frame rail without requiring the movement of thesecond bracket.

In another embodiment, a fuel system is provided that includes a fueltank and a support assembly. The fuel tank includes a centralcylindrical portion, a first neck portion that has a first boss at afirst end and a second neck portion that has a second boss at a secondend. The support assembly is configured to connect the fuel system to aside portion of a frame rail of a vehicle. The support assembly has afirst tank support portion, a second tank support portion, and a bracketsystem. The first tank support portion is configured to support thefirst neck portion of the tank. The second tank support portion isconfigured to support the second neck portion of the tank. The bracketsystem is coupled with the first tank support portion and the secondtank support portion. The bracket system is configured to be coupled toa frame rail at a frame rail position longitudinally between the firstneck portion of the fuel tank and the second neck portion of the fueltank.

In some variations, the tank is not being directly supported atlocations longitudinally between the first and second neck portions.

In another embodiment a fuel system is provided that includes a fueltank, a frame, and a step support. The fuel tank has a centralcylindrical portion, a first end and a second end opposite the firstend. The frame has a frame rail connection portion disposed on a vehicleside of the fuel system and a tank support portion disposed around oneor both of the first and second ends of the fuel tank. The step supportis configured to apply a load to the central cylindrical portion of thefuel tank.

In some embodiments, a fuel system is provided that includes an accessdoor on an end of the fuel system. The access door can be configured tobe moved to provide access to three or more components within the fuelsystem. One of the three or more components can be a filter. Forexample, in some embodiments, the access door can provide access to afilter, a defuel assembly, and a bleed valve. In some embodiments, theaccess door can provide access to a filter, a cylinder valve assembly,and a bleed valve.

In some configurations the fuel system enclosure, e.g., cover, has anelongated side opening that provides access to one or more components.The components can be mounted to one or more modular frame members,e.g., plates. The elongate opening enables service access to one or morecomponents that may be mounted in a modular way and accessible throughthe opening. For example, the same exterior enclosure with the elongateaccess opening can be used to enclose a wide range of internal componentlayouts while providing service, inspection and repair access to thecomponents thereof. In one example, three modular frame members areprovided, each with one or more serviceable component mounted thereto.The access opening can provide access to the components on all threemodular frame members.

In another form, an enclosure is provided with an access door assemblyhaving two stop positions. The assembly can have a first stop positioncorresponding to the door being rotated out of a position of covering anaccess opening. The assembly can have a second stop positioncorresponding to the door being rotated to a position of covering theaccess opening. In one of the positions, a hook comes to rest on a shaftof the access door assembly whereby the position of the door isrestrained. The door can be fixed in the restrained position byactuating a door locking clamp.

BRIEF DESCRIPTION OF THE DRAWINGS

The abovementioned and other features of the inventions disclosed hereinare described below with reference to the drawings of the preferredembodiments. The illustrated embodiments are intended to illustrate, butnot to limit the inventions. The drawings contain the following figures.

FIG. 1 is a perspective view of a cab of a heavy duty vehicle having afuel system mounted to a side portion of a frame rail of the vehicle;

FIG. 2 is a top view of a portion of a vehicle frame rail of a vehiclechassis having a fuel system according to one embodiment coupled to alateral portion of the frame rail;

FIG. 3 is a disassembled view of a portion of a fuel system bracket anda portion of a fuel system support assembly that has a plurality ofconnection positions;

FIGS. 3A-3B show a tank-side and frame rails side views, respectively,of a bracket assembly including a bracket portion and a fuel systemsupport assembly portion having a continuous range of connectionpositions;

FIG. 4 is a perspective view of a frame rail and bracket assembly formounting a fuel system according to one embodiment;

FIG. 5 is a vehicle side view of a fuel system and bracket assemblyaccording to one embodiment;

FIG. 6 shows detail 6-6 of the fuel system and bracket assembly of FIG.5;

FIG. 7-8 are top and perspective views of a bracket assembly accordingto one embodiment;

FIG. 9 is a cross-section of the bracket assembly of FIG. 2 taken at thesection plane 9-9 showing an elevation support of a fuel system bracket;

FIG. 10 is a cross-section of the bracket assembly of FIG. 2 taken atthe section plane 10-10 showing a transverse motion limit portion of aframe rail bracket;

FIG. 11 is a perspective view of the fuel system of FIG. 2 with thecover thereof removed showing neck support of the fuel tank;

FIGS. 11A-11B show a perspective view of an alternative configuration inwhich fuel system mounting positions are located outside of a projectionof the fuel tank, e.g., of a forward end of the fuel tank and/orrearward of a rearward end of the fuel tank;

FIG. 12 is a perspective view of a frame assembly of the fuel system ofFIG. 2 with the cover and the fuel tank removed;

FIG. 13 is an end view of the fuel system of FIG. 2 with an end portionof the cover of the system removed, showing a step assembly of the fuelsystem;

FIG. 13A is a detail view of a step assembly of FIG. 13 of the fuelsystem of FIG. 2;

FIG. 14 is an end view of the fuel system of FIG. 2 showing an accessdoor in an open position;

FIG. 14A is a perspective view of an end of the fuel system of FIG. 2showing the access door of FIG. 14 in an open position; and

FIG. 14B is an end view of the fuel system of FIG. 2 showing the accessdoor of FIG. 14 in a closed position.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

While the present description sets forth specific details of variousembodiments, it will be appreciated that the description is illustrativeonly and should not be construed in any way as limiting. Furthermore,various applications of such embodiments and modifications thereto,which may occur to those who are skilled in the art, are alsoencompassed by the general concepts described herein. Each and everyfeature described herein, and each and every combination of two or moreof such features, is included within the scope of the present inventionprovided that the features included in such a combination are notmutually inconsistent.

This application discloses a number of improvements in a side mountedfuel system 100 that, in some embodiments, provides more options inmating or mounting the fuel system 100 to a frame rail 42 of a vehicle40. See, e.g., FIG. 2 and Section I below. In some cases, theimprovement provide enhanced neck mounting of a fuel tank 102 of thefuel system 100. See, e.g., FIGS. 11-12 and Section II below. In somecases, the improvements make better use of available space for vehicleaccess steps a large fuel tank 102. See, e.g., FIG. 13 and Section IIIbelow.

I. Support Assembly for Frame Rail Connections

Some embodiments of the fuel system 100 provide more options for howmounting the fuel system 100 to a vehicle 40. The vehicle 40 can be orinclude a portion of a heavy-duty vehicle, such as a tractor unit forforming a tractor-trailer. The vehicle 40 includes a frame rail 42 thatsupports various components, such as forward wheels, rearward wheels,and a cab. The frame rail 42 can include a rigid member formed into ashape providing enhanced strength, such as having an I-beam or a Cshaped cross-section configuration. A C-shaped frame rail 42 can have along side 44 facing away from a center of the frame rail 42 and shortsides at a top and a bottom side thereof. The side 44 faces away from acentral, vertical forward-rearward plane. The side 44 can be equipped tosupport the fuel system 100 as well as a number of other components.

FIG. 2 shows an example of how the fuel system 100 and other componentscan be mounted to the frame rail 42. The fuel system 100 accommodatesthese other components to make better use of restricted space and/or toprovide compact configurations. For example, a fender 46 can be disposedat least partially over front wheels of the vehicle 40. In oneembodiment, a gap 47 separates a forward face of the fuel system 100from a rearward edge of the fender 46. A bracket assembly describedbelow can adjust the gap 47. As a further example, a shackle 50 coupledto the frame rail 42 can be configured to support a shock absorber. Theshock absorber configuration and/or the geometry of the vehicle 40 canlimit a desired position for the shackle 50.

The mounting location of the fuel system 100 can be shifted to betteraccommodate these other vehicle components. Also, the bracket assemblycomponent of the fuel system 100 to be shifted even if the rest of thefuel system 100 is not shifted to accommodate these other components.

A. Frame Rail Mounting Location Adjustment

FIGS. 2, 3, 5, and 11 show further aspects of mounting location for thefuel system 100. The fuel system 100 includes the fuel tank 102 that issupported by a support assembly, e.g. a fuel system frame 104. The fuelsystem frame 104 can also include a frame rail connection portion 106that can couple with a portion of a bracket assembly in a number ofdifferent positions. The frame rail connection portion 106 is providedon a vehicle side 100V of the fuel system 100. The frame rail connectionportion 106 can have a grid of mount features, which can include aplurality of mounting holes as discussed further below. The plurality ofmounting holes enables greater flexibility in placement of the bracketsused to connect the fuel system 100 to the frame rail 42. The pluralityof mounting holes enables greater flexibility in placement of the fuelsystem 100 on the frame rail 42. The plurality of mounting holes enablesgreater flexibility in placement of the fuel system 100 or the bracketsalong the frame rail 42. The fuel system 100 also includes a cover 105that in combination with the fuel system frame 104 encloses a spacearound the fuel tank 102.

FIGS. 2, 3 and 6-8 show details of a first bracket 108 and theconnection thereof to the frame rail connection portion 106 at arearward portion of the fuel system 100. In one embodiment, the framerail connection portion 106 is able to couple with a first bracket 108in more than one position. The first bracket 108 can be coupled to asecond bracket 112 to mount the fuel system 100 to the frame rail 42 asdiscussed further below. FIG. 3 shows that in one example, the framerail connection portion 106 can have an array of holes that allows thefirst bracket 108 to couple to the frame rail connection portion 106 ina plurality of discrete predefined positions. A first frame railconnection portion 106 can be coupled to a rearward position of the fuelsystem 100 in the orientation shown in FIG. 3 and a second frame railconnection portion 106 can be coupled to a forward position of the fuelsystem 100. The second frame rail connection portion 106 toward theforward position can be in an inverted orientation (rotated 180 degreesabout an axis into and out of the page). As a result, mounting features107 (e.g., fastener holes) of the rearward frame rail connection portion106 can be located toward the rear of the fuel system 100 and themounting features 107 of the forward frame rail connection portion 106can be located toward the front of the fuel system 100.

A first position 120 can be provided by a subset of the holes on theframe rail connection portion 106. For example a pair of holes locatedtoward a forward end of the array of holes, one above the other, can inpart define the first position 120. The forward pair of holes can belocated at a common longitudinal positon of the frame rail connectionportion 106. A second pair of holes can in part define the firstposition 120. The second pair of holes of the first position 120 can belocated at a common longitudinal position of the frame rail connectionportion 106 spaced apart from the first pair of holes of the firstposition 120. The first position 120 includes in this embodiment as aset of four holes including a forward most pair of holes on the framerail connection portion 106. This configuration allows the frame railconnection portion 106 to be coupled with the first bracket 108 at aforward-most position of the frame rail connection portion 106. Althoughthe first position 120 can include four holes, in some embodiments thefirst position 120 can include more or fewer holes than four holes, caninclude a different arrangements of holes, and can include positionsalong one or more slots as described further below. This can allow thefirst bracket 108 and a second bracket 112 coupled therewith to belocated forward relative to a second position 124 defined by a set ofholes of the array of holes on the frame rail connection portion 106.

In one embodiment, the second position 124 is defined by a pair of holesdisposed toward the rearward end of the frame rail connection portion106. The pair of holes of the second position 124 disposed toward therearward end can be disposed at a common longitudinal position of theframe rail connection portion 106. The second position 124 can befurther defined by a second pair of holes spaced forward of the firstpair of holes of the second position 124. The second pair of holes ofthe second position 124 can be located forward of, and in theillustrated example immediately adjacent to, the rearward pair of holesof the first position 120. Although the second position 124 include fourholes, the second position 124 could include more or fewer holes thanfour holes, can include different arrangements of holes, and can includepositions along one or more slots as described further below.

The frame rail connection portion 106 can define a third position 125between the first position 120 and the second position 124. The thirdposition 125 can be defined in part by a pair of holes located rearwardof, e.g., in one case immediately adjacent to, the forward holes of thefirst position 120. The third position 125 can be further defined by asecond pair of holes located rearward of, e.g., immediately rearward of,the rearward holes of the first position 120. Although the thirdposition 125 include four holes, the third position 125 could includemore or fewer holes than four holes, could include differentarrangements of holes, and could include positions along one or moreslots as described further below. Although three positions areillustrated in the frame rail connection portion 106, in otherembodiments there can be more or fewer positions defined by discrete,predefined holes in the frame rail connection portion 106. The positions120, 124, and 125 can also be forward, rearward and intermediate in asecond frame rail connection portion 106 which can be inverted and canbe located toward the forward end of the fuel system 100 as discussedabove.

The distance between the positions 120, 124, 125 can be any suitabledistance. For distance from the forward pair of holes of the firstposition, 120 to the forward pair of holes of the second position 124can be 100 mm in one embodiment. The distance from the second position124 to the third position 125, e.g., from the forward pair of holes ofthe first position 124 to the forward pair of holes of the secondposition 125 can be 50 mm in one embodiment. These distances can beuniform or can vary from one position to the next. For example, thedistance from the forward pair of holes of the first position 120 to theforward pair of holes of the second position 124 can be any of 200 mm,150 mm, 100 mm, 50 mm, 25 mm or more or less. The distance from thesecond position 124 to the third position 125, e.g., from the forwardpair of holes of the first position 124 to the forward pair of holes ofthe second position 125 can be any of approximately 160 mm, 155 mm, 152mm, 143 mm, 126 mm, 100 mm, 75 mm, 70 mm, 61 mm, 50 mm, 32 mm, 25 mm, or12 mm. The distance from the second position 124 to the third position125 can be three-quarters, two-thirds, one-half, one-third orone-quarter of the distance from the first position 120 to the secondposition 124.

FIG. 3 can further illustrate the positioning of a bracket assemblyrelative to the frame rail connection portion 106. A first bracket 108can include a portion illustrated in FIG. 3 that is configured to becoupled with the frame rail connection portion 106. The portion of thefirst bracket 108 can include a central flange 164. The central flange164 can project away from a bracket mounting base 166 that can include aplurality of mounting holes 109. The mounting holes 109 can be arrangedto match the holes corresponding to one or more position of the framerail connection portion 106. For example, the mounting holes 109 can bearranged in an array that includes a pair of mounting holes 109 on afirst side of the central flange 164 and a pair of mounting holes 109 ona second side of the central flange 164 opposite the first side. Thus,the mounting holes 109 can be aligned over the holes of the firstposition 120 and fasteners can be used to secure the bracket mountingbase 166 to the frame rail connection portion 106.

Advantageously, the groups of holes forming the first position 120, thesecond position 124, and the third position 125 can all be arranged atthe same spacing as the mounting holes 109 such that the bracketmounting base 166 can be aligned with the holes of any of thesepositions.

As noted above, the fuel system frame 104 can include the frame railconnection portion 106 located toward a rearward portion of the fuelsystem 100. The fuel system frame 104 can also include a second framerail connection portion 106 located toward a forward portion thereof. Astructural member 256 can couple the two frame rail connection portion106 together or they can be formed on a single unitary frame member. Theforward frame rail connection portion 106 can have the same or a similarconfiguration as the rearward frame rail connection portion 106, e.g.,with an array of holes defining a plurality of discrete spaced apartpositions. The forward frame rail connection portion 106 can be coupledwith bracket mounting base 166 of a third bracket 140, the third bracket140 configured to couple with a fourth bracket 152 to form a secondbracket assembly to couple the fuel system 100 to the frame rail 42.

The holes in the frame rail connection portions 106 (forward andrearward) enable several types of mounting configurations. For example,in one case, the longitudinal position of the fuel system 100 along theframe rail 42 can be determined. For example, the desired gap 47 can beprovided between a forward portion of the fuel system 100 and anadjacent component, such as the fender 46. In another example, thevehicle side 100V of the fuel system 100 can be disposed at leastpartially over a low profile component, such as the shackle 50.Potential interference at the forward end of the fuel system 100 withother components on the frame rail 42 can be determined. In one example,securing the third bracket 140 to the frame rail connection portion 106in the first position 120 would result in interference with another suchcomponent. The third bracket 140 can be moved to the second position 124or the third position 125 of the forward frame rail connection portion106. This allows the fourth bracket 152 to move to a frame rail positioncorresponding to the second position 124 or the third position 125 outof interfering position with such other component.

FIG. 2 shows the third bracket 140 in the second position 124 of theforward frame rail connection portion 106. FIG. 3 shows that in the caseof the rearward frame rail connection portion 106 the first position 120is a forward position, the second position 124 is a rearward position,and the third position 125 is an intermediate position between theforward and rearward positions. In in the case of the forward frame railconnection portion 106, the second position 124 is also the rearmostposition of the forward frame rail connection portion 106. For theforward frame rail connection portion 106 the second position 124 is theposition farthest from the mounting features 107. The position of thefirst bracket 108 on the rearward frame rail connection portion 106 canalso be selected to avoid interference with other components on theframe rail 42. In the illustrated embodiment, the bracket mounting base166 of the first bracket 108 can be secured to the fuel system 100 atthe first position 120, forward of the other positions 124, 125. Thisenables the rearward bracket assembly including the first bracket 108and the second bracket 112 to move forward out of a potentiallyinterfering position with other component on the frame rail 42. One cansee from the foregoing description that a number of permutation ispossible. In the illustrated embodiment, there are nine permutationsthat are possible for positioning the first bracket 108 and the thirdbracket 140. These positions can result in corresponding shifting of thesecond bracket 112 and the fourth bracket 152 as needed to provideconvenient connection, e.g., out of interference with other componentsconnected to the frame rail 42.

FIGS. 3A and 3B illustrate another embodiment of a frame rail connectionportion 106A that can be integrated into the fuel system frame 104. Theframe rail connection portion 106A can facilitate adjustment along acontinuous range of positions that are not predefined within the range.The frame rail connection portion 106A enables connection of the bracketmounting base 166 of the first bracket 108 or of the third bracket 140to the rearward frame rail connection portion 106A and to the frame railconnection portion 106A. In one embodiment, the frame rail connectionportion 106A includes a first slot 126 and a second slot 127. The firstslot 126 can be located generally above the second slot 127, e.g.,extending parallel to the second slot 127. Fasteners disposed throughthe mounting holes 109 of the bracket mounting base 166 of the firstbracket 108 can be located at any position along the first slot 126 andsecond slot 127.

The position of the first bracket 108 can be defined by initiallyloosely coupling the first bracket 108 to the frame rail connectionportion 106A at the first slot 126 and/or the second slot 127, e.g., bybolts or other fasteners. The position of the first bracket 108 can berefined by sliding the first bracket 108 along the frame rail connectionportion 106A to reach a user-defined position that is beneficial, e.g.,that avoids interference as needed. This allows positioning of a bracketassembly including the first bracket 108 to be selected during mountingto the vehicle 40 at any such position. In a fuel system frame 104 thatincludes forward and rearward frame rail connection portion 106A, thethird bracket 140 also can be coupled and positioned in this manner,allowing the end user to select the positions along the first slot 126and second slot 127 during mounting of the fuel system 100 to thevehicle 40.

B. Bracket Assemblies Providing Fastenerless Secure Connections

FIGS. 4-10 illustrate bracket assemblies that provide convenientconnection during fuel system-to-vehicle assembly. These bracketassemblies provide secure connections without requiring the bracketinterface to be further secured by bolts or other similar fasteners.Such fasteners can be provided prior to final shipment.

FIG. 4 shows that in one assembly a plurality of, e.g., two vehicle-sidebracket assembly portions can be coupled to the frame rail 42. Thesecond bracket 112 can be secured to the side 44 of the frame rail 42forward of the fourth bracket 152. The second bracket 112 can form aportion of a rearward bracket assembly with the first bracket 108. Thefourth bracket 152 can form a portion of a forward bracket assembly withthe third bracket 140. The brackets 112, 152 have similar constructionso the description of each one applies to the other. The second bracket112 includes a first portion 128 and a second portion 132. The secondportion 132 facilitates connection to the side 44 of the frame rail 42.For example, the second portion 132 can have an array of mounting holesthat can receives fasteners to be secured across the frame rail 42. Thefirst portion 128 can be a continuous member with, the second portion132 or can be part of an assembly therewith. The first portion 128 canallow the first bracket 108 to be lowered onto the second bracket 112.The first portion 128 can support the first bracket 108 so that the fuelsystem 100 coupled therewith is retained on the frame rail 42. A flangemember can be provided on the first bracket 108 can come to rest on topof the second portion 132 of the second bracket 112. A portion of thefirst bracket 108 can come to rest against a lower surface of the secondportion 132 of the second bracket 112. The fourth bracket 152 can have afirst portion 156 similar to the first portion 128 and a second portion160 similar to the second portion 132.

FIGS. 5-6 show details of the first bracket 108. The first bracket 108can be located rearward of the third bracket 140 on the vehicle side100V of the fuel system 100. The position of each of the brackets 108,140 can be selected by the user, e.g., based on the desire to avoidinterference with other components, as discussed above. In theillustrated embodiment, the first bracket 108 is in the first position120 of the rearward frame rail connection portion 106 and the thirdbracket 140 is in the second position 124 of the forward frame railconnection portion 106. The third bracket 140 can have the sameconstruction as the first bracket 108.

FIG. 6 shows the structure of the first bracket 108 in more detail. Thefirst bracket 108 includes a body including the central flange 164 andthe bracket mounting base 166. The bracket mounting base 166 can includea generally planar side configured to be secured against the frame railconnection portion 106. The central flange 164 can extend away from aside of the bracket mounting base 166 opposite the side configured tomate with the frame rail connection portion 106. The central flange 164can have opposite sides that face forward and rearward when the firstbracket 108 is mounted to the frame rail connection portion 106 and tothe frame rail 42. The first bracket 108 can include a mounting portionfor coupling the first bracket 108 to the second bracket 112. Themounting portion can include a bracket aperture 167 disposed along anaxis extending between the opposing sides of the central flange 164. Thebracket aperture 167 provides a point of connection between the firstbracket 108 and the second bracket 112 as discussed further below.

The first bracket 108 includes first and second support wings 168, 172.The support wings can have similar, e.g., mirror image, configurations.The first support wing 168 can include a mount portion 173 and avertical support 174. The mount portion 173 and vertical support 174form a flange configuration for resting on top of the second portion 132of the second bracket 112. The mount portion 173 is configured to extendalong a forward side of the central flange 164.

The mount portion 173 can be secured adjacent to the central flange 164through one or more resilient members, e.g., vibration dampers. Thevertical support 174 can extend rearward from an upper portion, e.g.,the top of, the mount portion 173. The vertical support 174 can beconfigured to rest on top of a portion of the second bracket 112 in apredefined position when the first bracket 108 and the second bracket112 are connected. The position can be defined at least in part by atransverse motion limit structure. In one embodiment, at least thevertical support 174 includes a configuration to resist bending. Forexample, the cross-section of the vertical support 174 can have a one ormore flanges that extend away from the loading surface, where forces areapplied between the vertical support 174 and the second bracket 112. Theflanges act in a manner similar to an I-beam to enhance the stiffness ofthe first support wing 168. The flanges can be seen as areas of greaterheight at the vehicle facing side and at the fuel system facing side ofthe first support wing 168.

The first support wing 168 also can include a rotational support 176.The rotational support 176 can include a projection configured to restagainst a lower portion, e.g., surface, of the second bracket 112. Therotational support 176 can help to enable the fuel system 100 to besupported on the frame rail 42 with the force of gravity being counteredat least in part through the rotational support 176. The weight isfurther supported through the first support wing 168 and the secondsupport wing 172. A clearance is provided between a top surface of therotational support 176 and a bottom surface of the vertical support 174to receive the first portion 128 of the second bracket 112. This isdescribed in greater detail below in connection with FIGS. 7-10.

The connection between the first support wing 168 and the second supportwing 172 and the central flange 164 can be through a resilient member,such as a damper or a vibration isolator. FIG. 6 shows that a firstresilient member 180 provided between the first support wing 168 and thecentral flange 164. The first resilient member 180 can be configured asa stepped cylinder having a smaller diameter section on a centralportion of the outside surface there. The first resilient member 180 canhave larger diameter section on ends thereof on both sides of thecentral portion. The larger diameter section of one end of the firstresilient member 180 can be disposed between opposing surfaces of thefirst support wing 168 and the central flange 164. The larger diametersection of another end of the first resilient member 180 can be disposedbetween opposing surfaces of the second support wing 172 and the centralflange 164. As shown, bolts can be disposed through the first resilientmember 180 and the second resilient member 182 to secure the firstsupport wing 168 to the central flange 164. The first resilient member180 and the second resilient member 182 are resilient, e.g.,compressible, such that loads applied during operation of the vehicle 40from the road are not directly transferred to the fuel system 100 butrather are absorbed to some extent and modulated in the first resilientmember 180 and the second resilient member 182. In one variation, thefirst resilient member 180 and the second resilient member 182 can becombined providing a single member with multiple aperture for securingthe wings to the central flange 164.

A third resilient member 184 provided in the bracket aperture 167modulates similar loads that could be applied through the point ofconnection at the bracket aperture 167 between the first bracket 108 andthe second bracket 112. In one modified embodiment, connection at thebracket aperture 167 can be provided without any vibration isolation ordamping, e.g. by directly bolting the first bracket 108 to the secondbracket 112 at this location. In a further modified embodiment, thefirst resilient member 180 and the second resilient member 182 can beeliminated. The connection points between the first and/or secondsupport wing 168, 172 can be rigid e.g., direct connection withoutintervening resilient members.

FIGS. 4, 9 and 10 illustrate aspects of the second bracket 112. In oneembodiment, the second bracket 112 and the fourth bracket 152 have thesame construction. So, description of either the second bracket 112 orof the fourth bracket 152 applies to the other these two brackets. Thesecond bracket 112 includes a first portion 128 and a second portion132, as discussed above. The first portion 128 can include a generallyplanar structure at least on a side configured to face the side 44 ofthe frame rail 42. The first portion 128 can have one or a plurality ofapertures for securing the second bracket 112 to the frame rail 42 usingfasteners. The second bracket 112 can have a vertical support 186 oneach of a forward and a rearward side of an internal space 188 disposedon a lateral side of the second bracket 112. The internal space 188 canbe disposed on a side opposite the side of the second bracket 112 thatfaces the side 44 of the frame rail 42 when the second bracket 112 iscoupled thereto.

The vertical supports 186 can be formed flanges of the second bracket112 located forward and rearward of the internal space 188. The internalspace 188 can be configured, e.g., sized and shaped, to receive thecentral flange 164 and the mount portion 173 of the first bracket 108.The vertical supports 186 can be configured to reside immediately belowand in contact with the first support wing 168 and the second supportwing 172 when the first bracket 108 is mated with the second bracket112. The vertical support 186 can have a geometry to enhance stiffness,e.g., with a support flange disposed beneath the vertical support 186 incontact with the second portion 132.

The second bracket 112 can include a transverse motion limiter 196configured to control the position of the first bracket 108 relative tothe second bracket 112 when these brackets are assembled together. Thetransverse motion limiter 196 can include one or more, e.g., two, ridges198 disposed along a top surface of the vertical support 186. The ridges198 can have a height of about 0.1 inch. In some embodiments, the ridges198 have a height of 0.2 inch, 0.3 inch, 0.4 inch, 0.5 inch, 0.6 inch,0.7 inch, or more than 0.7 inches. The ridges 198 can have a height thatis 5% of the thickness of the first support wing 168 or the secondsupport wing 172 in a vertical direction, e.g., of the transversestiffening structure of the support wing. The ridges 198 can have aheight that is 10% of the thickness of the first support wing 168 or thesecond support wing 172 in a vertical direction. The ridges 198 can havea height that is 25% of the thickness of the first support wing 168 orthe second support wing 172 in a vertical direction.

The support wings 168, 172 and the vertical supports 186 can allow thefuel system 100 to be mounted to the frame rail 42 during assemblywithout any additional fasteners. The support wings 168, 172 and thevertical supports 186 can have apertures for allowing bolts to morepermanently connect the second bracket 112 to the first bracket 108, asdiscussed further below. The second bracket 112 also can include abracket aperture 190 configured to be aligned with the bracket aperture167 when the brackets are assembled. The alignment of the bracketaperture 190 on the second bracket 112 and the bracket aperture 167 onthe first bracket 108 can be facilitated by a clearance gap 192 formedthrough the second bracket 112. The clearance gap 192 can allow aportion of the body of the first bracket 108 disposed about the bracketaperture 167 to overlap with the first portion 128 of the second bracket112.

FIGS. 7-10 illustrate methods of assembling the fuel system 100 to theframe rail 42. FIG. 7 shows that the fuel system 100 with the firstbracket 108 attached thereto at the frame rail connection portion 106can be placed adjacent to the second bracket 112, which is coupled tothe side 44 of the frame rail 42. The first bracket 108 and be placed ator slightly above the elevation of the second bracket 112. FIG. 8 showsthat the first bracket 108 can be moved into the internal space 188. Forexample, the portion of the central flange 164 away from the vehicleside 100V can be moved into the internal space 188. The mount portion173 of the first support wing 168 can be moved into the internal space188. The first bracket 108 and the fuel system 100 coupled thereto canbe moved down relative to the second bracket 112 from the position shownin FIG. 8 until a bottom side of the first support wing 168 (and of thewing 172) is disposed above, on top of or in contact with the verticalsupport 186. Specifically the vertical support 174 of the first supportwing 168 of the first bracket 108 can be placed on top of the verticalsupport 186 of the second bracket 112. A vertical support of the wing172 of the first bracket 108 can be placed on top of the verticalsupport 186 of the second bracket 112. FIG. 9 shows that when so placed,the rotational support 176 of the first bracket 108 can come intocontact with a lower surface of the second bracket 112. The lowersurface can be disposed on a transverse portion of the second bracket112 disposed between the vertical support 186 and facing or partlybounding the internal space 188. The rotational support 176 can limitrotation of the fuel system 100 relative to the frame rail 42, whichrotation can be a function of the outboard weight of the fuel system100.

FIG. 10 shows that the transverse position of the fuel system 100relative to the frame rail 42 can be at least partially controlled bythe transverse motion limiter 196, e.g., by ridges 198 located on top ofthe vertical support 186. The ridges 198 can be configured, e.g., sizedand positioned to abut an in-board face of the first bracket 108, e.g.,of an inboard portion of one or both of the support wings 168, 172. Saidanother way, as the fuel system 100 and the first bracket 108 movetoward the frame rail 42 the in-board side of one or both of the wings168, 172 will abut the ridges 198 and such abutment can be detected bythe assemble device or personnel positioning the fuel system 100. Thiswill confirm that the first bracket 108 and the second bracket 112 areat least temporarily connected. This position will also bring thebracket aperture 167 in line with the bracket aperture 190, as discussedabove.

These configurations allow the fuel system 100 to be at leasttemporarily secured to the frame rail 42 without any additionalconnecting devices, e.g., without any bolts passing through both of thebrackets 108, 112. FIGS. 9 and 10 shows that subsequently, e.g., beforesending the vehicle 40 out on the road at the end of assembly, bolts canbe passed through both brackets 108, 112 to provide a more secureconnection.

The manner of assembling the third bracket 140 to the fourth bracket 152can be the same as that discussed above in connection with the firstbracket 108 and second bracket 112. Additionally, the bracket assemblymethods can include selecting a position from a discrete number ofpositions or along a continuous range, for connection of the firstbracket 108 to the frame rail connection portion 106. The positionselected can be based on the presence of other components on the framerail 42, e.g., of a frame cross-member. The position of the firstbracket 108 can follow a preferred location of the second bracket 112 toavoid interference with such components. The position of the firstbracket 108 can follow a preferred location of the second bracket 112 toshare a mount location with another member. The position of the secondbracket 112 can follow a preferred location of the first bracket 108.

II. Neck Mounted Fuel Tank Assemblies for Side Mounted Fuel Systems

The fuel system 100 provides a number of advantages, some of whichrelate to the manner in which the fuel tank 102 thereof is supportedwithin the cover 105. The fuel tank 102 is supported in novel ways, e.g.at ends thereof and with arcuate supports that provide advantagespositioning relative to the frame rail 42. In some embodiments, the fuelsystem frame 104 is configured with low profile mounting configurations,to maintain mounting locations between ends of the cover 105 of the fuelsystem 100 to provide low profile mounting configurations. In someembodiments, the fuel system frame 104 has extended mounting locationconfigurations to position the mounting locations outside the areaopposite the fuel tank 102 to leave the frame rail 42 free fromconnections opposite the fuel tank 102.

A. Low Profile Mounting Configurations

FIG. 11 shows the fuel system 100 with the cover 105 removed. The fueltank 102 has a central cylindrical portion 204, a first neck portion208, and a second neck portion 212. The first neck portion 208 includesa first boss 220 located at the end of the fuel tank 102. The first boss220 is a sealed portion of the fuel tank 102 that can have fuel conduitcoupled therewith to enable filling fuel into and drawing fuel from thefuel tank 102. The first boss 220 is also sufficiently rigid to enablethe fuel tank 102 to be supported at that location as discussed furtherbelow. The fuel tank 102 can have a second boss 228 disposed at a secondend 232 of the fuel tank 102. The fuel tank 102 also can include apolymeric liner at least in the central cylindrical portion 204 thereof.The liner can be secured to a first dome assembly including the firstboss 220 and to a second dome assembly including the second boss 228.

In some embodiments the fuel tank 102 is supported only at the firstneck portion 208 and the second neck portion 212. In such embodiments,no straps are provided in the central cylindrical portion 204 nor is thefuel tank 102 supported in any other manner between the first end 224and the second end 232. In other embodiments, one or more supportingstraps also can be provided between the first end 224 and the second end232 to support the fuel tank 102.

FIGS. 11 and 12 show that the fuel system frame 104 that includes theframe rail connection portions 106 (forward and rearward) can alsoinclude tank end support portion 258 that are secured to the first end224 and the second end 232 of the fuel tank 102. The tank supportportions 258 extend across a diameter of and around forward and rearwardends of the fuel tank 102. The tank support portions 258 on forward andrearward ends are connected by a structural member 256 to provide aconcave frame structure into which the fuel tank 102 is received. Thefuel system frame 104 can further include a collision load member 300 ona lateral side to absorb at least some of the load of an impact. Thefuel system frame 104 can also include a lower frame assembly 254 forsupporting the cover 105 and/or for enhancing the strength of the fuelsystem frame 104. The lower frame assembly 254 can be disposed aroundand under a portion of the fuel tank 102 circumferentially between thepositions of the tank support portions 258. FIG. 11 shows that the fuelsystem frame 104 including the tank support portions 258, the lowerframe assembly 254 and the collision load member 300 can form anenclosure disposed about half of the circumference of the fuel tank 102such that the fuel tank 102 can be placed within the frame from theother half circumference. In one assembly technique, the second tanksupport portion 268 is separated from the first tank support portion 260of the tank support portion 258. The first tank support portion 260 andthe second tank support portion 268 can be separated on both ends of theframe assembly. The first boss 220 and the second boss 228 can be placedinto the concave ends of the first tank support portion 260. Thereafter,the second tank support portion 268 can be secured to the first tanksupport portion 260 to form the tank support portion 258 around thefirst boss 220 and the second boss 228. Fasteners, such as bolts canthen be advanced through apertures in the first tank support portion 260and the second tank support portion 268 provide a rigid connection inthe tank support portion 258. In some embodiments, the lower frameassembly 254 is assembled to the tank support portion 258 on each end ofthe frame assembly after the second tank support portion 268 is securedto the first tank support portion 260.

FIG. 12 shows more detail of the structure of the tank support portion258. The tank support portion 258 includes a first tank support portion260 and a second tank support portion 268. The first tank supportportion 260 can be disposed on a rearward side of the fuel system 100.The second tank support portion 268 can be located on the forward sideof the fuel system 100. The first and second tank support portions 260,268 can be similar, e.g., mirror images of each other. The first tanksupport portion 260 will be discussed in detail. The description of thefirst tank support portion 260 and the second tank support portion 268can be applied to each other.

The first tank support portion 260 can include a first tank bracket 276and a second tank bracket 280. The first tank bracket 276 can include afirst ribbed side 282 and a second ribbed side 284. The first ribbedside 282 can have a plurality of, e.g., two, three, or four, or morethan four ribs to enhance the strength of the first tank bracket 276.The ribs can enhance the stiffness of the brackets.

The second tank bracket 280 can include a first block 286 disposed at anend thereof configured to engage the fuel tank 102. The first block 286includes a first support surface 288 configured to engage the fuel tank102. The second tank bracket 280 also can include a second block 292.The second block 292 includes a second support surface 294 configured toengage the fuel tank 102. One or both of the first block 286 and thesecond block 292 can include a thicker portion of the first tank bracket276 and the second tank bracket 280, as shown in FIG. 11. The blocks286, 292 can have a thickness sufficient to secure fasteners therein andtherebetween. A space 296 defined between the first support surface 288and the second support surface 294 can be configured to receive thefirst boss 220 of the fuel tank 102. The first tank bracket 276 and thesecond tank bracket 280 can be separate components to be joined asappropriate, e.g., by one or more bolts through the first block 286 andthe second block 292.

FIGS. 11 and 12 show that the fuel system frame 104 can be configured tolocate the mounting points or locations inward of the ends of the fuelsystem 100. As discussed above, the first bracket 108 and the thirdbracket 140 are secured to the frame rail connection portions 106 awayfrom the first end 224 and the second end 232 of the fuel tank 102. Forexample, the first tank bracket 276 can be formed such that a firstportion thereof extends to the first block 286 and a second end iscoupled with or extends to the frame rail connection portion 106. Thefirst tank bracket 276 can comprise an L-shaped or curved constructionwith the first block 286 on one end and the frame rail connectionportion 106 on an end opposite the first block 286. The L-shape or curvecan have an inner angle or portion that includes the first ribbed side282. The L-shape or curve can have an inner portion that follows thecurvature of the fuel tank 102. The inner angle or portion can beoriented toward the mounting space for the tank.

FIGS. 11 and 12 show that this configuration allows the frame railconnection portion 106 to be located within the fuel system frame 104 ata longitudinal position of the fuel system 100 that is toward thecentral cylindrical portion 204 of the fuel tank 102, e.g., at or overthe cylindrical portion 204. For example the second bracket 112 and/orthe fourth bracket 152 can be aligned with, e.g., intersected by orcentered on a plane containing the ends of the central cylindricalportion 204 (e.g., the liner portion) of the fuel tank 102. In otherwords, a projection of the first end 224 and/or the second end 232 ofthe fuel tank 102 into the plane of the second portion 132 of the secondbracket 112 would show the second bracket 112 to be between theprojected ends. FIG. 2 shows that the second bracket 112 and the thirdbracket 140 can thus be spaced from the ends of the fuel system 100 withthe cover 105 in place.

The curved configuration of the first tank bracket 276 can allow thecover 105 to be shaped to create space for components on the frame rail42. As shown in FIG. 2 the shape of the first tank bracket 276 on theforward side of the fuel system 100 can enable the cover 105 to have anangled surface 103 creating space for the shackle 50 (or other lowprofile component mounted to the frame rail 42). By moving the mountpoints on the frame rail connection portion 106 away from the forwardand/or the rearward ends of the fuel system 100, a more compact mountingarrangement or footprint for the fuel system 100 can be provided on theframe rail 42. Also, the mount point locations on the frame railconnection portion 106 provide more options for supporting the fuelsystem 100 and other components on the frame rail 42. For instance, theshackle 50 can be mounted to the frame rail 42 opposite the angledsurface 103, e.g., rearward of the projection 49 (see FIG. 2).

B. Extended Mounting Location Configurations

While reducing the longitudinal extent of the footprint of the fuelsystem 100 between the second bracket 112 and the fourth bracket 152 canbe beneficial, in some embodiments it is desirable to avoid locatingmounting points between the ends of the fuel tank 102 or even betweenthe forward and rearward faces of the cover 105. FIGS. 11A and 11B showthat the fuel system frame 104 can have another frame mountingconfiguration in which the first tank bracket 276 on the forward and/orthe rearward ends of the fuel system 100 are re-oriented so that thefirst ribbed side 282 faces away from the space in which the fuel tank102 is mounted.

The first block 286 can be configured to mount to the second tankbracket 280 in at least two different orientations, e.g., as shown inFIG. 12 for a low profile frame rail mounting configuration or as inFIGS. 11A and 11B for a frame rail configuration avoiding a length A ofthe frame rail 42 opposite the fuel tank 102. Fastening apertures on thefirst block 286 of the first tank bracket 276 and on the second block292 of the second tank bracket 280 can align in a configuration wherethe internal angle of the first tank bracket 276 faces toward the fueltank 102 or where the internal angle of the first tank bracket 276 facesaway from the fuel tank 102. In a configuration for reversing the firsttank bracket 276, mount features for supporting the lower frame assembly254 can be provided on both of the short sides that extend between thefirst ribbed side 282 and the second ribbed side 284. The cover 105 canbe modified to enclose the reversed first tank bracket 276 on one orboth of the forward and rearward sides of the fuel system 100. Endportions of an overall enclosure of the fuel system 100 that includesthe cover 105 can be modified to have an opening through which the firsttank bracket 276 can extend to position the frame rail connectionportion 106 at an exposed location for mounting to the frame rail 42.For example, the cover 105 can be disposed circumferentially around thefuel tank 102. Sheet or plate members can be coupled with the ends ofthe circumferential cover 105. The sheet or plate members can cover thenends, e.g., the end shown in FIG. 13 to form an overall enclosure. Whenso extended the forward frame rail connection portion 106 is locatedforward of the second end 232 of the fuel tank 102 and the rearwardframe rail connection portion 106 is located rearward of the first end224 of the fuel tank 102.

The configuration of the fuel system frame 104 illustrated in FIGS. 11Aand 11B provides an arrangement whereby a length of the frame rail 42between the ends of the fuel system 100 and even between the first end224 and the second end 232 of the fuel tank 102 is free of connectionlocations for the fuel system 100. The fuel system 100 is disposed at orover this portion of the frame rail 42. The frame rail 42 at theconnection free length can be used for mounting other components betweenthe fuel system 100 and the rail or on an in-board side of the framerail 42 (opposite the side 44). For example, internal trusses of thechassis of which the frame rail 42 is a part can be located along thislength without concern for interference between such trusses and thebrackets coupled to the forward and rearward frame rail connectionportions 106.

III. Access Step Support Configurations

In some cases it is desired to include a larger fuel tank 102, e.g., atank of more than 24 inches in diameter, e.g., 25 inches, 26 inches, or27 inches in diameter. This desire for larger size of the fuel tank 102conflicts with a limitation on the lateral extent of the fuel system 100when applied to the vehicle 40. With reference to FIG. 13, it is desiredto maximize dimension B (tank diameter) while not increasing dimension C(distance from frame rail mount location to outward most extent of thefuel system 100). Another constraint is that if more than one step isprovided, an upper step should be in-board of an upper step boundary302. The upper step boundary 302 provide enough clearance for a user tocomfortably lift his or her foot from a lower step 324 to a step member312 of a step support assembly 308. In some embodiments, the fuel system100 includes enhanced access step configurations that enable the fuelsystem 100 to be meet these conflicting requirements.

FIGS. 2 and 13 shows that a step support assembly 308 can have anexternal portion disposed outside the cover 105 to be accessible to theuser for accessing the cab of the vehicle 40. The external portion ofthe step support assembly 308 can include a step member 312 that isformed to provide a low profile on a lateral side of the fuel system 100and in some embodiments a second (e.g., a lower) step portion 324. Thestep member 312 can be supported directly on an outside surface 320 thefuel tank 102 by a compressible member 316, discussed further below. Thedirect support on the outside surface 320 of the fuel tank 102 helps tomaintain a compact configuration in the width direction, e.g., tomaintain as small a dimension C as possible (see FIG. 13).

Unlike many conventional steps, in some embodiments the step member 312is not rectangular in cross-section. FIG. 13A shows one profile of thestep member 312 in which an upper surface 328 that is exposed and ontowhich the user can step. The upper surface 328 of the step member 312can be generally horizontal to provide a flat surface for stepping. Afirst lateral edge 332 of the step member 312 can be disposed adjacentto the outside surface 320 of the fuel tank 102. In one embodiment, thestep member 312 can be formed from a sheet. An edge of the sheet can befolded to form the first lateral edge 332. In particular, the edge ofthe sheet can be folded at least partially under the upper surface 328.The folded under portion can be formed to generally follow the curvatureof the tank. In one example, the folded under portion can have aninternal angle of less than 90 degrees or an external angle of greaterthan 270 degrees. The folded over portion can provide a length overwhich apertures for coupling to the compressible member 316 can beprovided, as discussed further below. The step member 312 can have asecond lateral edge 336 disposed opposite the first lateral edge 332.The second lateral edge 336 can comprise the lateral most extent of thestep member 312. The second lateral edge 336 can be located inward ofthe upper step boundary 302.

The step member 312 can include a lower surface 340 that extends from alower portion of the second lateral edge 336 toward the tank whenassembled to the tank, as shown in FIG. 13A. The lower surface 340 canbe disposed at an angle to the second lateral edge 336, e.g., at aninternal angle that is greater than 90 degrees, or at an external anglethat is greater than 180 degrees. As shown in FIG. 13A, the lowersurface 340 preferably extends at a non-horizontal angle toward theoutside surface 320 of the fuel tank 102. The internal angle between thelower surface 340 and the second lateral edge 336 is preferably about120 degrees.

As discussed above, the step member 312 can be formed from a sheet. Inone embodiment, an edge of the sheet can be folded over to define thelower extent of the lower surface 340. The folded over portion caninclude one or a plurality of apertures to facilitate securing thecompressible member 316 and a portion of the cover 105 between the stepmember 312 and the fuel tank 102. In one embodiment a folded overportion of the step member 312 extends away from the lower surface 340.The folded over portion can extend generally in a direction along thefuel tank 102. The folded over portion can be curved to follow thecurvature of the fuel tank 102 or can be generally straight but disposedalong a direction generally tangential to the outside surface 320 of thefuel tank 102. The folded over portion can extend at an internal angleto the lower surface 340 of about 90 degrees. Other angles are possible.In some embodiment, the folded over ends of the step member 312 aresufficiently flexible to allow the ends to conform to the tank shapewhen the step member 312 is attached to the fuel system 100.

The non-rectangular shape of the step member 312 as formed and whenapplied to the outside surface 320 of the fuel tank 102 enable the fuelsystem 100 to maximize the length of the upper surface 328 whileremaining in-board of the upper step boundary 302. FIGS. 13 and 13Aillustrate one example of a non-rectangular step configuration that helpmaximize the size of the tank (dimension B—see FIG. 13) while not overlyextending the width dimension of the fuel system 100 (dimension C—seeFIG. 13).

The step support assembly 308 also enhances compactness and step size byproviding a more direct connection between the step member 312 and thefuel tank 102. In one embodiment, folded over end portions of the stepmember 312 are mounted to the outside surface 320 through interveningcompressible members 316. The compressible member 316 are placed on anupper half of the fuel tank 102 such that a stepping force is opposed bythe outside surface 320 of the fuel tank 102. In particular, the loadwill be applied through the compressible members to the outside surface320. In one embodiment, the step member 312 is supported by one or aplurality of compressible member 316, e.g., by two, four, six or eightcompressible member 316. The compressible member 316 can be formed of apolymeric material, such as one or more of a neoprene, a rubbermaterial, nitrile rubber, natural rubber, and EPDM. The compressiblemember 316 can be generally circular in shape and can have a diameter ofabout one-half inch to two inches. In other specific examples, thecompressible member 316 has a diameter of about one inch, about twoinches, about three inches, or about four inches. FIG. 13 shows that thecover 105 can be disposed between the step member 312 and an outsidesurface of the compressible member 316.

The lower step 324 can be coupled with the collision load member 300. Inone embodiment, the cover 105 is disposed between the lower step 324 andthe collision load member 300. The lower step 324 can be intersected bythe upper step boundary 302 such that a lower foot can rest on the lowerstep 324 and an upper foot of a user can be lifted up and over thesecond lateral edge 336 of the step support assembly 308 and comecomfortably to rest across the upper step boundary 302 and onto theupper surface 328 of the step member 312.

In some embodiments the first bracket 108 can have a number ofconnection points to more permanently connect the first bracket 108 tothe second bracket 112. For example, a plurality of, e.g., two,apertures can be formed through upper segments of the first support wing168 and the second support wing 172 to secure the first bracket 108 tothe second bracket 112.

IV. Access Door Configurations

In some cases it is desired to include an access door 400 on one or moreends of the fuel system 100. The access door 400 can be configured tomove between a closed position and one or more open positions. Movingthe access door 400 to an open position can uncover an opening 420 on anend of the fuel system 100 and provide access to certain componentswithin the fuel system 100. In some cases, the opening 420 is verticallyelongated to provided access along a majority, e.g., along 75 percent,of the height of the side of the cover 105. The access door 400 can havea shape matching that of the opening 420.

In some embodiments, the access door 400 can be coupled to the cover 105of the fuel system 100. For example, as shown in FIGS. 14, 14A, and 14B,the access door 400 can be rotatably coupled to an end portion of thecover 105 by a pivot 402. In some embodiments, the pivot 402 isconfigured to provide some amount of resistance to rotation of theaccess door 400 (e.g., friction), thereby preventing the access door 400from freely rotating about the pivot 402 under its own weight andallowing the access door 400 to remain fixed in any position. Theresistance provided by the pivot 402 can be easily overcome by applyingadditional force to the access door 400, such as by manually moving theaccess door 400 about the pivot 402.

In some embodiments, the axis of rotation of the access door 400 extendsthrough the pivot 402, perpendicular to the outer surface of the endportion of the cover 105, allowing the access door 400 to be rotatedbetween open and closed positions (e.g., rotated clockwise and/orcounterclockwise) while keeping an inner surface of the access door 400parallel to the outer surface of the end portion of the cover 105. Thisconfiguration can advantageously allow the access door 400 to be openedand closed even when space is limited between components of the fuelsystem 100 (e.g., when an outwardly swinging door would not be usable).For example, in some embodiments, the access door 400 can be opened andclosed when the fuel system 100 is side-mounted and there is 4 inches orless clearance between the fuel system 100 and another component mountedto the frame rail 42 adjacent to the system 100. The access door 400 canbe shaped such that the access door 400 does not interfere with portionsof the fuel system frame 104 and brackets.

In some embodiments, the access door 400 can be secured in a closedposition using a fastener 410. In some embodiments, the fastener 410 cancomprise a bolt, rod, knob, lever, and/or button. For example, in someembodiments, the fastener 410 comprises a knob threaded on a rod. Insome embodiments, the fastener 410 is fixed in a particular location onthe fuel system 100 (e.g., does not change position when the access door400 changes position). For example, the fastener 410 can be coupled tothe outer surface of the cover 105.

In some embodiments, a portion of the access door 400, such as a flange404, can be configured to be positioned between a lower surface of thefastener 410 and the outer surface of the cover 105 when the access door400 is in the closed position. In some embodiments, the fastener 410 isconfigured to be tightened against a portion of the access door 400 toprevent rotation of the access door 400 about the pivot 402. The flange404 can comprise a hook portion that can be disposed around a shaft ofthe fastener 410 to at least temporarily fix the closed position of theaccess door 400. For example, the fastener 410 can be configured to berotated or otherwise adjusted to secure (e.g., compress) a portion ofthe access door 400, such as the flange 404, tightly against the outersurface of the cover 105, thereby securing the access door 400 inposition relative to the rest of the fuel system 100. In someembodiments, rotation of the fastener 410 in a first direction (e.g.,clockwise) tightens the fastener 410 against a portion of the accessdoor 400 and rotation of the fastener 410 in a second direction (e.g.,counterclockwise), opposite the first direction, releases the accessdoor 400 from its closed position, allowing the access door 400 to berotated about the pivot 402.

In some embodiments, it is desired to include a holder 412 configured tohold the access door 400 in one or more positions, such as in an openposition. For example, as shown in FIG. 14, the holder 412 can becoupled to the cover 105 and configured to prevent the access door 400from rotating beyond a particular location when the access door 400 isin an open position (e.g., by abutting an edge of the access door 400).This can prevent the access door 400 from blocking or covering a portionof the opening 420 when the access door 400 is in an open position. Theholder 412 can be a protrusion, rod, screw, and/or clamp.

In some embodiments, the access door 400 can provide access, through theopening 420, to three or more components within the fuel system 100.This configuration can make it easier, faster, and/or morecost-efficient to service components of the fuel system 100. Forexample, in some embodiments, as illustrated in FIGS. 14 and 14A, theaccess door 400 can provide access to a filter 422, a cylinder valveassembly 424, a bleed valve 426, a defuel assembly 430 comprising adefuel valve 432 and a defuel nozzle 434, an electronic control unit(ECU) 428, and/or fuel assembly plumbing.

In some embodiments, the access door 400 can provide access, through theopening 420, to components of the fuel system 100 that are mounted onmore than one modular plate. The opening 420 can provide access tocomponents of more than one subassembly. For example, the access door400 can provide access to components of the fuel system 100 that aremounted on a first plate 440A, a second plate 440B, and/or a third plate440C. In some embodiments, the defuel assembly 430 and the filter 422are mounted on different plates 440A, 440C. In some embodiments, thedefuel assembly 430 and the ECU 428 are mounted on the same plate 440A.In some embodiments, the filter 422 and the cylinder valve assembly 424are mounted on the same plate 440C.

Although these inventions have been disclosed in the context of certainpreferred embodiments and examples, it will be understood by thoseskilled in the art that the present inventions extend beyond thespecifically disclosed embodiments to other alternative embodimentsand/or uses of the inventions and obvious modifications and equivalentsthereof. In addition, while several variations of the inventions havebeen shown and described in detail, other modifications, which arewithin the scope of these inventions, will be readily apparent to thoseof skill in the art based upon this disclosure. It is also contemplatedthat various combination or sub-combinations of the specific featuresand aspects of the embodiments may be made and still fall within thescope of the inventions. It should be understood that various featuresand aspects of the disclosed embodiments can be combined with orsubstituted for one another in order to form varying modes of thedisclosed inventions. Thus, it is intended that the scope of at leastsome of the present inventions herein disclosed should not be limited bythe particular disclosed embodiments described above.

1. A fuel system, comprising: a fuel system frame for supporting a fueltank that comprises a forward end having a forward-extending boss, arearward end having a rearward-extending boss, and a central portionextending longitudinally between the forward end and the rearward end,the fuel system frame comprising a frame rail connection portion and atank end support portion, the tank end support portion extendinglaterally from the frame rail connection portion and configured tosupport one of the rearward-extending boss or the forward-extendingboss, the frame rail connection portion comprising a first mountingposition and a second mounting position, the second mounting positionspaced longitudinally apart from the first mounting position; a firstbracket configured to connect to the frame rail connection portion ofthe fuel system frame at the first mounting position or at the secondmounting position to support the fuel system frame from either the firstmounting position or the second mounting position; and a second brackethaving a first portion configured to mate with the first bracket and asecond portion configured to connect to a vehicle frame rail.
 2. Thefuel system of claim 1, wherein the tank end support portion isconfigured to support the rearward-extending boss, wherein the fuelsystem frame further comprises a second frame rail connection portionand a second tank end support portion, the second tank end supportportion extending laterally from the second frame rail connectionportion and configured to support the forward-extending boss, whereinthe first bracket and the second bracket are configured to support arearward portion of the fuel system frame, and wherein the fuel systemfurther comprises a third bracket and a fourth bracket configured tosupport a forward portion of the fuel system frame.
 3. The fuel systemof claim 2, wherein the third bracket is configured to connect to thesecond frame rail connection portion of the fuel system frame at one ofa plurality of longitudinally spaced apart mounting positions to supportthe fuel system frame from one of the plurality of mounting positions.4. The fuel system of claim 1, wherein a resilient member is disposedbetween the fuel system frame and the second portion of the secondbracket.
 5. The fuel system of claim 4, wherein the resilient member isdisposed within the first bracket.
 6. The fuel system of claim 1,wherein the first bracket comprises a central flange and first andsecond support wings extending forwardly and rearwardly of the centralflange.
 7. The fuel system of claim 6, wherein a resilient member isdisposed between the central flange and one of the first or secondsupport wings.
 8. The fuel system of claim 7, wherein the resilientmember comprises a first resilient member and the fuel system furthercomprises a second resilient member disposed between the central flangeand the other of the first or second support wings.
 9. The fuel systemof claim 8, further comprising a third resilient member disposed at abracket connection portion spaced away from the first and second supportwings.
 10. The fuel system of claim 6, wherein a vertical supportprojects laterally from at least one of the first and second supportwings to support the second bracket from below.
 11. The fuel system ofclaim 6, wherein a transverse motion limiter projects vertically from atleast one of the first and second support wings to constrain transverserelative movement between the first bracket and the second bracket. 12.The fuel system of claim 11, wherein the transverse motion limitercomprises ridges having a height of at least 25 percent of the verticalthickness of the first portion of the second bracket.
 13. The fuelsystem of claim 1, wherein the first mounting position and the secondmounting position are disposed along a continuous slot formed in theframe rail connection portion of the fuel system frame.
 14. The fuelsystem of claim 1, wherein the first mounting position is at leastpartially defined by a first plurality of apertures in the frame railconnection portion, wherein the second mounting position is at leastpartially defined by a second plurality of apertures in the frame railconnection portion, wherein the first plurality of apertures comprisesat least one aperture that is not part of the second plurality ofapertures, and wherein the second plurality of apertures comprises atleast one aperture that is not part of the first plurality of apertures.15. A fuel system, comprising: a fuel tank comprising a centralcylindrical portion, a first neck portion comprising a first boss at afirst end and a second neck portion comprising a second boss at a secondend; a support assembly configured to connect the fuel system to a sideportion of a frame rail of a vehicle, the support assembly comprising; afirst tank support portion configured to support the first neck portionof the tank; and a second tank support portion configured to support thesecond neck portion of the tank; a bracket system coupled with the firsttank support portion and the second tank support portion; wherein thebracket system is configured to be coupled to a frame rail at a framerail position longitudinally between the first neck portion of the fueltank and the second neck portion of the fuel tank.
 16. The fuel systemof claim 15, wherein the tank support portion comprises a first tankbracket and a second tank bracket, the first bracket having a first sidefacing the fuel tank and a second side facing away from the fuel tank.17. The fuel system of claim 16, wherein the first tank bracketcomprises a first block having a first support surface configured to bedisposed about the first boss and the second tank bracket comprises asecond block having a second support surface configured to be disposedopposite the first support surface and to enclose a space about thefirst boss.
 18. The fuel system of claim 15, wherein a collision loadmember is coupled with the first tank support portion and with thesecond tank support portion.
 19. A fuel system, comprising: a fuel tankcomprising a central cylindrical portion, a first end and a second endopposite the first end; a frame comprising a frame rail connectionportion disposed on a vehicle side of the fuel system and a tank supportportion disposed around one or both of the first and second ends of thefuel tank; a step support configured to apply a load to the centralcylindrical portion of the fuel tank.
 20. (canceled)
 21. (canceled) 22.(canceled)
 23. (canceled)
 24. The fuel system of claim 2, furthercomprising the fuel tank, wherein the rearward-extending boss issupported by the tank end support portion, and the forward-extendingboss is supported by the second tank end support portion.
 25. The fuelsystem of claim 24, wherein the fuel tank is supported only at theforward-extending boss and the rearward extending boss.
 26. The fuelsystem of claim 24, wherein the first, second, third, and fourthbrackets are each positioned longitudinally between theforward-extending boss and the rearward-extending boss.
 27. The fuelsystem of claim 2, wherein the frame rail connection portion and thesecond frame rail connection portion are connected together by astructural member such that the frame rail connection portion, the tankend support portion, the structural member, the second frame railconnection portion, and the second tank end support portion provide aconcave frame structure into which the fuel tank can be received withthe structural member positioned laterally inward of the central portionof the fuel tank.
 28. The fuel system of claim 27, further comprising anoutboard member connected to lateral outboard ends of both of the tankend support portion and the second tank end support portion, theoutboard member configured to be positioned laterally outward of thecentral portion of the fuel tank.
 29. The fuel system of claim 28,wherein the outboard member comprises a collision load member configuredto absorb at least some of a load of an impact.
 30. The fuel system ofclaim 28, wherein at least one of the tank end support portion or thesecond tank end support portion comprises a multi-part structure that isseparable at a portion of the support configured to support therearward-extending or forward-extending boss.
 31. A fuel system,comprising: a fuel system frame for supporting a fuel tank, the fuelsystem frame comprising a frame rail connection portion that comprises afirst mounting position and a second mounting position, the secondmounting position spaced longitudinally apart from the first mountingposition; a first bracket configured to connect to the frame railconnection portion of the fuel system frame at the first mountingposition or at the second mounting position to support the fuel systemframe from either the first mounting position or the second mountingposition; and a second bracket having a first portion configured to matewith the first bracket and a second portion configured to connect to avehicle frame rail.
 32. The fuel system of claim 31, wherein the firstmounting position and the second mounting position are disposed along acontinuous slot formed in the frame rail connection portion of the fuelsystem frame.
 33. The fuel system of claim 31, wherein the firstmounting position is at least partially defined by a first plurality ofapertures in the frame rail connection portion, wherein the secondmounting position is at least partially defined by a second plurality ofapertures in the frame rail connection portion, wherein the firstplurality of apertures comprises at least one aperture that is not partof the second plurality of apertures, and wherein the second pluralityof apertures comprises at least one aperture that is not part of thefirst plurality of apertures.
 34. The fuel system of claim 31 whereinthe first bracket comprises a flange positioned between first and secondsupport wings, and the first bracket further comprises one or moreresilient members disposed between the flange and one or both of thefirst or second support wings.